The present invention is related to a system with optical or radio remote control for locking and unlocking motor vehicles. Such systems are disclosed, for example, in pending application U.S. Ser. No. 773,635, filed Nov. 8, 1991.
This known system for locking and unlocking motor vehicles is an example of a so-called unidirectional system, in which namely the (re)initialization is carried out without dialog between the transmitter and the receiver. The invention was admittedly developed initially for this known unidirectional system for locking and unlocking motor vehicles. However, it is not restricted just to unidirectional locking and unlocking systems, and not at all to just that specific known unidirectional system for locking and unlocking motor vehicles, but can also be used in the case of bidirectional systems, in which a more or less extensive dialog takes place.
One problem in the case of such initializable systems for locking and unlocking motor vehicles is that unallowed and unintended (re)initializations are to be reliably avoided as far as possible. The invention therefore relates in particular to corresponding technical prerequisites for creating the initialization readiness of the system for locking and unlocking motor vehicles.
In addition, it is known per se to install a diagnostic interface in a motor vehicle, namely for example a special connector fitted in the engine compartment. By means of this diagnostic interface, the state of electronic and/or mechanical motor vehicle units can be tested or interrogated, for example the current engine characteristics, the state of the brakes and the serviceability of a wide variety of other electronic units such as airbag-control units and ABS characteristics--as a rule only in appropriately equipped authorized workshops.